Joker with a month of prep vs Pennywise

Batman and the Gotham heroes are off in deep space dealing with some cosmic JLA thing for several months when Joker escapes Arkham. Joker is prepping to thoroughly make the most of such a long vacation from fighting the Batfamily when he hears about how he's got competition killing and terrifying Gothamites: Pennywise has moved into Gotham. He declares that there can only be one killer-clown in Gotham, and that's him! He preps for a month and then begins hunting Pennywise. Does he succeed?

Likely. Pennywise had a few major weaknesses: arrogance, limitations of the form it took, and the conviction of its enemies. In the book, the kids were able to overcome It, because they believed they could. I doubt Joker's convictions would be less than a bunch of scared kids. I should also add that Joker obviously wouldn't be dealing with the pants-shitting terror that the kids dealt with.

The only real problem is if Pennywise knows about Joker and his characteristics. Pennywise played around with kids, because he didn't think they were anything to worry about. If he for any reason thought Joker could be a threat, he might just go for a quick kill. In that case, Joker could be in a lot of trouble.

It's kind of ambiguous, but I get the impression that it's kind of like the True Faith thing with crosses repelling vampires: just believing in it isn't enough, you have to Believe with a capital B, a level of imagination and certitude that is so rare as to almost be a superpower. But as I said, the book only implies this in an ambiguous manner.

IT's true self is essentially Entropy-Itelf, an abstract entity comparable to Marvel's Death and Eternity and so forth. However, IT can't interact directly with the physical realm without an avatar, and the avatar's power-level is vague but almost certainly not on the level of IT's true self, since that self is present in all decay throughout the cosmos. Moreover, creating the avatar also effectively created a voodoo-doll for that cosmic abstract, allowing beings far weaker than ITself to hurt IT through the voodoo-doll/avatar called Pennywise.

In a comic, IT would choose Joker to be ITs avatar/servant, only for Joker to absorb ITs power and assume ITs place as the ultimate agent of chaos. Batman gets help from Superman and Dr. Fate to trick Joker into relinquishing the power, and Joker goes back to Arkham while IT is banished from the earthly realm.

IT's true self is essentially Entropy-Itelf, an abstract entity comparable to Marvel's Death and Eternity and so forth. However, IT can't interact directly with the physical realm without an avatar, and the avatar's power-level is vague but almost certainly not on the level of IT's true self, since that self is present in all decay throughout the cosmos. Moreover, creating the avatar also effectively created a voodoo-doll for that cosmic abstract, allowing beings far weaker than ITself to hurt IT through the voodoo-doll/avatar called Pennywise.

This feels like you read waaaaay too much into shit

"Comparable to Marvel's Death and Eternity" ?? What in the fuck

Even the Crimson King was just a crazy old man, you're giving Stephen King way too much credit

In a comic, IT would choose Joker to be ITs avatar/servant, only for Joker to absorb ITs power and assume ITs place as the ultimate agent of chaos. Batman gets help from Superman and Dr. Fate to trick Joker into relinquishing the power, and Joker goes back to Arkham while IT is banished from the earthly realm.